title: Noninvasive assessment of left ventricular force-frequency relationships by measuring carotid arterial wave intensity during exercise stress.
abstract: BACKGROUND
  Evaluation of the contractile state of the left ventricle during exercise is important in drawing up a protocol of cardiac rehabilitation. It has been demonstrated that color Doppler- and echo tracking-derived carotid arterial wave intensity is a sensitive index of global left ventricular (LV) contractility.
  
  
  OBJECTIVE
  We assessed the feasibility of measuring carotid arterial wave intensity and determining force-frequency (contractility-heart rate) relationships (FFR's) during exercise totally noninvasively.
  
  
  METHODS
  We measured carotid arterial wave intensity with a combined color Doppler and echo tracking system in 15 healthy young male volunteers (age 20.8 ± 1.3 years) at rest and during exercise. FFR's were constructed by plotting the maximum value of wave intensity (WD1) against heart rate (HR).
  
  
  RESULTS
  WD1 increased linearly with an increase in HR. The goodness-of-fit of the regression line of WD1 on HR in each subject was very high (r2 0.67 ~ 0.91, p < 0.0001 respectively). The slope of the WD1-HR relation ranged from 0.31 to 1.52 [m/s(3)(beat/min)].
  
  
  CONCLUSIONS
  A global LV FFR can be generated in healthy young volunteers with an entirely noninvasive combination of exercise and wave intensity. These data should show the potential usefulness of FFR in the context of cardiac rehabilitation.
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Sugawara
authors.forename: Y
authors.initials: Y
authors.lastname: Ogasawara
authors.forename: I
authors.initials: I
authors.lastname: Suminoe
authors.forename: T
authors.initials: T
authors.lastname: Izumi
authors.forename: O
authors.initials: O
authors.lastname: Hiramatsu
authors.forename: F
authors.initials: F
authors.lastname: Kajiya
mesh_terms: D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000502:physiology*; D018618:Echocardiography, Doppler, Color; D015444:Exercise; D006339:Heart Rate; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D016276:Ventricular Function; D055815:Young Adult